Anodizing is an electrochemical process which grows a dense oxide layer on certain metals, including aluminum, niobium, tantalum, titanium and tungsten. The thickness of this layer and its properties vary greatly depending on the metal. For example, the anodizing process converts an aluminum surface into an extremely hard, durable, corrosion resistant, long-lasting aluminum oxide, which has diverse and important applications. Further, this surface can be processed to have a variety of colors as well as finishes, such as reflective or matte.